Port-closing device.



No. 826,060. 'PATBNTED JULY 17. I906. G; L. PRATT. PORT CLOSING DEVICE.

APPLICATION. FILED AUG. 14, 1905.

2 BHEBTSQSHEET 1-- 1n: NORRIS PETERS co., wasnmcrou. D. c.

- PATENTED JULY 17; 1906. V G. L. PRATT.

' PORT CLOSING DEVICE.

APPLIOATION FILED AUG.14, 1905.

2 sums-sum 2.

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W a 7L PATENT OFFICE.

GEORGE LEWIS PRATT, OF ATLANTA, GEORGIA.

PORT-CLOSING DEVICE.

Specification of Letters Patent.

Patented July 17, 1906.

Application filed August 14, 1905. Serial No. 274,209.

Much difficulty has been experienced in the past in pulverizing machines or mills and the like placed side by side in a chain or gang and having, perhaps, only one common con.

nected chamber to receive the pulverulent material coming from the mills of back draft and consequent sifting of dirt into and up through a machine which may be temporarily idle in the series or gang, thus undesirably and unnecessarily clogging the working parts thereof.

The object of my invention, therefore, is in a simple and efficient manner to remedy this difiiculty by preventing such back draft and consequent sifting of dirt into and up through the mill while the same is idle.

With this object in view the invention consists in the novel construction, combination, and arrangement of parts, as will be hereinafter fully described and claimed.

In the accompanying drawings, forming part of my specification, I have shown my invention applied to a pulverizing mill or machine, it being understood that 1 do not confine its application to use in such connection, as it can be used wherever desired.

In the drawings, Figure 1 is a central vertical section through a form of pulverizingmachine, showing the application of my invention thereto. Fig. 2 is a fragmentary view in top plan of my invention, showing the slidemember ports fully registering with the base-ports. Fig. 3 is a View similar to Fig. 2, but showing the slide member shifted, so that its ports are not in full, but only partial, register with the ports in the base; and Fig. 4 is a fragmentary vertical section taken on line a (L, Fig. 2.

Referring to the drawings in detail, A designates a pan for the reception of the material to be pulverized and being preferably circular in shape. In this pan work rollers B, carried by shafts C, as usual, a wear-ring D being preferably disposed within the pan, against which the rollers operate.

Adjacent to or formed as a part of pan A is a base F, provided with ports h therethrough. Around the upper outer edge of the base is secured an annular upright drum f, confining dust and pulverulent material, issuing through a conical screen E, secured around the top of the pan to the interior of the pulverizing-mill and directing such pulverulent material so passing through said screen downward through ports t (hereinafter more specifically mentioned) and h and preventing the pulverulent material from sifting in all directions exterior of the pulverizing-mill.

Disposed between the drum F and the screen E, and preferably supported on top of the base F and the pan A, is a slide member I, preferably ring or circularly shaped and provided with port-holes 'L therein, adapted to register with ports h through base F. Carried by the slide member I is a rack i Suitably journaled in the base F is a shaft J, carrying at its outer end appropriate means for its rotation, as a hand-Wheel j, and at or near its inner end a pinion 1' meshing with rack 17. When slide member I is in the position shown in Fig. 2, port-holes i therein and ports h in base F are in register, and passage therethrough is permitted to a suitable compartment or receptacle. (Not shown.) A revolution of handwheel will blank such port-holes and ports.

As there may be a tendency to lift or rise on the part of the slide member I under certain conditions, as when moved, as described, and as there is also necessarily some friction or binding of the same When in operation, I overcome these tendencies by a combined guard and antifriction device, which may be as follows: Revolubly mounted on screw-pins is, (preferably three in number,) set in top of pan A or in top of base F, or in both pan and base, adjacent the edge of slide member I, are rollers K, in juxtaposition to the edge of the slide member and having annular flanges k overlying slide member I and constituting guards acting at all times to prevent the slide member from rising or lifting. It will be seen that the revolubly-mounted rollers K prevent any possible binding or friction, which would otherwise occur, thus obviating wear and rendering easy the operation of the slide member.

In the operation of the machine as the material is ground in pan A by the rollers working therein it is continuously thrown up against screen E and the liner particles thereof sift through the screen and thence through registering port-holes t and ports ft to a receiving-compartment. Should the mill be idle, hand-wheel is revolved to the right, say, whereupon all port-holes and ports are blanked, preventing any back draft and consequent sifting of fine dust and dirt up through ports I), and into the idle mill, such back draft being caused by the other working machines in the gang which dump into one common receiving-compartment pulverulent material.

My device is thus exceedingly simple in construction and most efficient in operation and adds materially to the value of any pulvleriging-mill, to which it may be readily ap- As many minor changes may be made in the details of construction, I do not wish to be limited to the exact construction shown.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a pulverizing machine or mill, a pan adapted for the reception of the material to be pulverized, and within which work the usual crushing-rollers, a base in juxtaposition to the outer edges of such pan and having ports therethrough, an upright surrounding drum or casing secured to the upper edge of the base, a slide member disposed within the space inclosed by the surrounding drum or casing, and having ports therethrough adapted to register with the ports in the base, and also having a rack on its under surface, and a rotatable shaft j ournaled in the base and provided toward its inner end with a pinion disposed beneath said slide member and adapted to mesh with its rack.

2. In a pulverizing machine or mill, a pan adapted for the reception of the material to be pulverized, and within which works the usual crushing-rollers, a base in juxtaposition to the outer edges of such pan and having ports therethrough, an upright surrounding drum or casing secured to the upper edge of the base, a slide member disposed within the space inclosed by the surrounding drum or casing, and having ports therethrough adapted to register with the ports in the base, and also having a rack on its under surface, a rotatable shaft journaled in the base and provided toward its inner end with a pinion disposed beneath said slide member and adapted to mesh with its rack, and antifriction devices disposed intermediate the base and the slide member.

3. In a pulverizing machine or mill, a pan adapted for the reception of the material to be pulverized, and within which work the usual crushing-rollers, a base in juxtaposition to the outer edges of such pan and hav ing ports therethrough, an upright surrounding drum or casing secured to the upper edge of the base, a slide member disposed within the space inclosed by the surrounding drum or casing, and having ports therethrough adapted to register with the ports in the base, and also having a rack on its under surface, a rotatable shaft journaled in the base and provided toward its inner end with a pinion disposed beneath said slide member and adapted to mesh with its rack, and means for holding the slide member against upward movement.

4. In a pulverizing machine or mill, a pan adapted for the reception of the material to be pulverized, and within which work the usual crushing-rollers, a base in juxtaposition to the outer edges of such pan and having ports therethrough, an upright surrounding drum or casing secured to the upper edge of the base, a slide member disposed within the space inclosed by the surrounding drum or casing, and having ports therethrough adapted to register with the ports in the base, and also having a rack on its under surface, a rotatable shaft journaled in the base and provided toward its inner end with a pinion disposed beneathsaid slide member and adapted to mesh with its rack, and combined antifriction devices and guards for holding the slide member against upward movement.

5. In a pulverizing machine or mill, a pan adapted for the reception of the material to be pulverized, and within which work the usual crushing-rollers, a base in juxtaposition to the outer edges of such pan and having ports therethrough, an upright surrounding drum or casing secured to the upper edge of the base, a slide member disposed within the space inclosed by the surrounding drum or casing, and having ports therethrough adapted to register with the ports in the base, and also having a rack on its under surface, a rotatable shaft journaled in the base and provided toward its inner end with a pinion disposed beneath said slide member and adapted to mesh with its rack, and antifriction devices, comprising screw-pins set in the upper edge of the base, and rollers revolubly carried thereby and bearing against the edge of the slide member.

6. In a pulverizing machine or mill, a pan adapted for the reception of the material to be pulverized, and within which work the usual crushing-rollers, a base in juxtaposition to the outer edges of such pan and having ports therethrough, an upright surrounding drum or casing secured to the upper edge of the base, a slide member disposed within the space inclosed by the surrounding drum or casing, and having ports therethrough adapted to register with the ports in the base, and also having a rack on its under surface, a rotatable shaft j ournaled in the base and provided toward its inner end with a pinion disposed beneath said slide member and adapted to mesh with its rack, and combined antifriction devices and guards for holding. the I In testimony whereof I affix my signature slide member against upward movement, in the presenc e of two subscribing Witnesses. comprising screw-pins set in the upper edge of the base, and rollers revolubly carried LEWIS PRATT thereby and bearing against the edge of the Witnesses: slide member, and having annular flanges T. BARTOW FORD, overlying the slide member. S. B. MCKINNEY. 

